<script language="JavaScript">
<!--
var str = '11:11';
var com = '12:00';

if (str > com)
{
    alert(str + ' more the ' + com);
} else if (str == com)
{
    alert(str + ' is equal ' + com);
} else
{
    alert(str + ' less than ' + com);
}
//-->
</script>